The present invention relates generally to electrified trains and more specifically a termination for a power and communication trainline for electro-pneumatic brakes.
The locomotive on freight trains generally include a pneumatic as well as electrical connectors. Locomotives include a leading end and a trailing end electrical and pneumatic couplers. When one or more locomotives are used in a consist, the adjacent couplers are connected. Thus, the leading coupler of the lead locomotive and the trailing coupler of the last locomotive are not coupled. Covers or dummy couplers have been provided for the electrical coupler to protect them from the debris and the environment.
In a freight train, historically, there has been no electrical connection to the cars which form part of the train. There has only been pneumatic connections. With the incorporation of electro-pneumatic braking in the freight train industry, the electrical connection of an electro-pneumatic brake control line through the locomotives and each of the cars of the freight train is provided. Each of the locomotives and cars include a leading and trailing electro-pneumatic trainline connector. This carries the control signals as well as the power throughout the train, including the locomotives and the cars. In the present design under consideration by the industry, a two wire system carries 230 VDC and communication signals.
While the trailing connector of the last locomotive is connected to the leading connector of the first car in the train, the lead connector of the lead locomotive is still exposed. In the prior art, the last car in the freight car train has an end-of-train device. With the advent of the electro-pneumatic trainline, the end-of-train device is connected to the trailing connector of the last car. The end-of-train device includes a line termination circuit. To achieve maximum communication performance, the trainline communication should also have a lead end termination. Since trains usually have more than one locomotive, a system must be devised to determine the lead end of the train and provide termination. Termination circuits should not be active in the trailing locomotives.
An example of an electro-pneumatic train brake system is described in U.S. Pat. No. 5,673,876 to Lumbis et al. This is an automatic electric trainline with safety interlock. This Patent is incorporated herein by reference.
The present invention includes a leading end termination connector on each locomotive and an EP line termination circuit in the leading end termination connector. The leading end connector of a locomotive not connected to an adjacent locomotive is connected to the leading end termination connector. This provides protection for the non-connected leading end connector as well as providing appropriate electrical termination on the EP line. Wherein the train includes a consist of a plurality of locomotives, the leading end trainline connector of the first locomotive is connected to the leading end termination connector of the first locomotive. The termination circuit is an impedance matching circuit. Wherein the EP line is an AC line, the termination circuit is an AC impedance matching circuit. An end-of-train device is also connected to the trailing end trainline connector of a car not connected to an adjacent car. The end-of-train device is a portable device and includes an impedance matching circuit. The EP trainline includes at least two conductors which carry power and control signals. The trainline connectors extend from a junction box and the termination connector is connected to the junction box of the leading end trainline connector. A lanyard connects the termination connector to the junction box of the leading end connector.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.